Laserfiche WebLink
T <br /> 2908 Benjamin Holt Drive <br /> Page 2 <br /> I <br /> I <br /> Soil Vapor Extraction and Air Sparging,Performance Evaluations <br /> The soil vapor extraction and air sparging systems have not operated continuously. During <br /> the first quarter operating period the systems only operated for 34% of the time. Benzene <br /> concentrations destroyed during the first quarter were not obtained. In order to evaluate <br /> system performance and to accuratelyestimate and report the cumulative destruction, <br /> benzene destruction concentrations must be determined at least quarterly. <br /> Co-mingled Plume <br /> i <br /> As you are aware, monitoring well BHD1, placed to identify the northern boundary of <br /> groundwater contamination plume, is located on the property currently used by Chevron to <br /> distribute petroleum products. The Chevron site also has a groundwater plume and there . <br /> is not clear demarcation between the two plumes. Chevron has recently committed, in <br /> correspondence dated July 17, 1996, to starting up an interim remediation system by <br /> November 29, 1997. It may be helpful if you increase coordination/system evaluation <br /> efforts and develop some type of agreement whereby remediation of the co-mingled plume <br /> can proceed to regulatory closure. <br /> If you have any questions, comments, or wish to schedule a site inspection, please contact <br /> me at (209) 468-0337. <br /> Donna Heran, RENS, Director <br /> Environmental Health Division <br /> Mary Meays, Senior RENS Margaret Lagorio, REHS <br /> Site Mitigation Unit Supervisor . <br /> I <br /> I <br /> MM\2908BENH <br /> cc: Elizabeth Thayer, CVRWQCS <br /> cc: Jay Johnson, EMCON <br /> i <br /> i <br /> 1 <br /> i <br /> 1 <br /> i <br />